In a running MICROS Retail OSCAR POS application, the server, client and backup server control the communication of the transaction data with the database.
Under normal conditions, the optional MICROS Retail OSCAR POS backup server runs as a passive database backup server for the MICROS Retail OSCAR POS server. The MICROS Retail OSCAR POS server is the only client for the MICROS Retail OSCAR POS backup server. Under normal operation conditions, i.e. the MICROS Retail OSCAR POS server is not offline, no transactions from other clients working within the network will be accepted by the MICROS Retail OSCAR POS backup server. The communication of all active clients within the network is operated exclusively via the MICROS Retail OSCAR POS server and its main database.
The MICROS Retail OSCAR POS server sends all changes in its database as a copy to the MICROS Retail OSCAR POS backup server. The calculations and processing of the transaction data are carried out by the MICROS Retail OSCAR POS server exclusively. The MICROS Retail OSCAR POS backup server stores the data sent by the MICROS Retail OSCAR POS server as copies in the backup database.
As long as the MICROS Retail OSCAR POS server is online, all clients working within the network communicate with the MICROS Retail OSCAR POS server exclusively.
The MICROS Retail OSCAR POS Backup Server can have the following operation states:
All transactions in offline mode are marked specially in both databases.
If changes have been made in a database, there will be an automatic update of both databases after establishing a connection between the MICROS Retail OSCAR POS server and the MICROS Retail OSCAR POS backups server
All transactions in the offline mode will be marked in a special way in both databases.
If changes have taken place in one of the databases, an automatic update of both databases will be implemented after the connection between the MICROS Retail OSCAR POS server and backup server has been established.
Normally, the MICROS Retail OSCAR POS server database will be copied to the MICROS Retail OSCAR POS backup server. If the MICROS Retail OSCAR POS backup server has been switched over to be the MICROS Retail OSCAR POS server in the offline mode or because the MICROS Retail OSCAR POS server main database has been destroyed, the MICROS Retail OSCAR POS backup server database will be copied to the MICROS Retail OSCAR POS server after the connection has been established.
While the database is copied, the writing access to the database of the sending server is locked, i.e. active terminals do not send transactions during the copy process. This can cause delays in the terminal operation. There will be no message to the active operator.
If the MICROS Retail OSCAR POS backup server has been in the operation state "run standalone" without being switched over to being the MICROS Retail OSCAR POS server, all transaction data will be lost after the copy process from the MICROS Retail OSCAR POS server to the MICROS Retail OSCAR POS backup server. All clients within the network store a copy of all transactions that have been carried out in the offline mode in their own client database. When the MICROS Retail OSCAR POS server and backup server are online, all clients within the network establish the connection to the MICROS Retail OSCAR POS server again. Afterwards, all offline transactions will be transferred automatically from the clients to the MICROS Retail OSCAR POS server.
The
behaviour of all clients that have been switched over to the backup server
during the MICROS Retail OSCAR POS server /backup server offline period is the same as if
they had all been offline.
The clients that kept the connection to the MICROS Retail OSCAR POS server during the MICROS Retail OSCAR POS
server /backup server offline period keep on working as usual.
Attention:
If the basic data of the MICROS Retail OSCAR POS server is
modified after the MICROS Retail OSCAR POS backup server has been switched over to the
operation mode "run
as master" though the network connection between the two
servers is disturbed, there might be data loss.
Before the MICROS Retail OSCAR POS backup server is switched over to be the MICROS Retail OSCAR POS server, you should make sure that the physical connection between these two servers is interrupted. Switch off the MICROS Retail OSCAR POS server or terminate the network connection while the MICROS Retail OSCAR POS backup server is in the operation mode "run as master".
Do not start the basic data maintenance at the MICROS Retail OSCAR POS server unless all network problems have been solved and the MICROS Retail OSCAR POS server and MICROS Retail OSCAR POS backup server are online. The MICROS Retail OSCAR POS backup server will be switched over to the operation mode "backup operation" after the connection to the MICROS Retail OSCAR POS server has been re-established.